Yeah... speaking of LIfegrip, I need to write more about it next week...

Archangel gives the best returns when you use 4-5 stacks of evangelism. I'll make a chart a week or two after Cataclysm comes out that gives the exact numbers of costs and returns. Miss Medicina covered it a while back but I wasn't going to make one here until the values were finalized. You can read her findings here: http://missmedicina.blogspot.com/2010/09/cataclysm-evangelism-archangel-algebra_18.html

PoH's mana cost reduction did help it, but there just isn't a huge need for it in 5-man heroics at the moment. In 10- and 25-man content though, it's definitely getting use. We'll talk more about that in a week or two.

Like Sakkula says above, it might not have been nerfed, just got a tooltip revision. I'm looking into it. But honestly? Atonement is super OP. Casting Smite is JUST like casting a full heal, and it stacks up Evangelism. You can basically use Archangel every time it's off CD and you'll never have to worry about mana at all. This means there is no decision making for disc, your Smite just auto heals the lowest health target in melee range which only rarely isn't the target you wanna heal. The only reason to cast heal is if you want to reduce the duration of Weakened Soul, but that's pretty situational (like green boss in Halls of Origination I'll try to get extra shields out - if this doesn't make sense don't worry about it now. I'll explain later.)